A Study of the Efficacy of Fecal Microbiota Transplantation(FMT) in the Treatment of Depression

Subjects will receive FMT capsules (10\^12 CFU/capsule) in addition to their usual antidepressant treatment. Subjects will continue to receive FMT capsules for 8 weeks. New SSRI antidepressants (fluoxetine, citalopram, escitalopram, sertraline, paroxetine, and fluvoxamine) recommended by current treatment guidelines can be used during this period, and the effective therapeutic dose of the drugs can be added within 1 week.

Participants will receive a placebo capsule with the same color, appearance, and smell as the FMT capsule, in addition to their usual antidepressant treatment. Placebo capsules contained the food probiotic Lactobacillus (10\^12 CFU per capsule). Subjects will continue to receive placebo capsules for 8 weeks. New SSRI antidepressants (fluoxetine, citalopram, escitalopram, sertraline, paroxetine, and fluvoxamine) recommended by current treatment guidelines can be used during this period, and the effective therapeutic dose of the drugs can be added within 1 week.